Right Ventricular Pressure Waveform Monitoring in Cardiac Surgery

Early Identification and Prediction of Right Ventricular Dysfunction and Failure in Critically Ill Patients: An Observational Non-Interventional Cohort Study

RV dysfunction has been associated with increased mortality in the ICU and cardiac surgical patients. Thus, early identification of RV dysfunction at less severe stages will allow for earlier intervention and potentially better patient outcomes.

However, so far, no studies have reported prospectively the prevalence of abnormal RV pressure waveform during cardiac surgery and in the ICU. The investigator's primary hypothesis is that the prevalence of abnormal RV pressure waveform occurs in more than 50% of cardiac surgical patients throughout their hospitalization. Those patients with abnormal RV pressure waveform will be more prone to post-operative complications related to RV dysfunction and failure in the OR and ICU.

Right ventricular (RV) dysfunction is mostly associated to a decrease in contractility, right ventricular pressure overload or right ventricular volume overload. RV dysfunction can occur in a number of clinical scenarios in the intensive care unit (ICU) and operating room (OR): pulmonary embolism, acute respiratory distress syndrome (ARDS), septic shock, RV infarction, and in pulmonary hypertensive patients undergoing cardiac surgery.

Unfortunately, identifying which patients will develop RV dysfunction and then progress towards RV failure have proven difficult. One of the reasons for delaying the diagnosis of RV dysfunction could be the lack of uniform definition, especially in the perioperative period. Echocardiographic definitions of RV dysfunction have been described: RV fractional area change (RVFAC) < 35 %, tricuspid annular plane systolic excursion (TAPSE) < 16 mm, tissue Doppler S wave velocity <10 cm/s, RV ejection fraction (RVEF) <45% and RV dilation. However, echocardiographic indices alone are insufficient in describing RV function. The diagnosis of fulminant RV failure is more easily recognised as a combination of echocardiographic measures, compromised hemodynamic measures and clinical presentation. RV dysfunction is inevitably associated with absolute or relative pulmonary hypertension because of the anatomic and physiological connection between the RV and pulmonary vascular system. The gold standard for measuring pulmonary pressure is still the pulmonary artery catheter. However, RV output can initially be preserved despite of pulmonary hypertension. It is therefore mandatory that early, objective, continuous, easily obtainable and subclinical indices of RV dysfunction are found and validated to initiate early treatment of this disease.

Inclusion Criteria:

-Male or female patients, age 18 and older, undergoing cardiac surgery and receiving standard of care monitoring utilizing a pulmonary artery catheter.

Exclusion Criteria:

• Emergency surgery or inability to obtain consent
• Concomitant diseases such as pericardial constriction, congenital heart disease, severe valvular regurgitation, right ventricular systolic dysfunction, or right ventricular infarction.